Based on the pre-commands of the title menu, button 1 is always selected, so force selection of button 1 is unnecessary.
Did you modify the title menu in any way? As you can see, the Titles pane under VTS1 is highlighted in red, saying that “Title 2 has no entry PGC set”. If you did not, then what your DVD Recorder created is illegal and is not compliant to DVD spec. Your DVD may not work on other standalones if you select titles 2-17.
Maybe this could be the cause why your button is sometimes not highlighted, I’m not sure. Until you have the DVD with no warnings, there’s no way to tell.
Anyway, this is the same situation as we discussed in your previous thread.
If you wanted to jump to a specific chapter, it is better to put the menu in the VTS1/Menus/PGC1 (Root menu). This I have outlined the steps for you, and even uploaded the revised files for you in your previous thread. You can use it as a reference.
However, another alternative is to keep the title menu as is. But the button command, Jump VMG Title x, must be changed, and a few other areas must be modified as well. It’s not really complicated once you have the methodology down. I can provide details if you’re interested.